摘要
对Al-Mg-Sc-Zr合金轧制板材进行搅拌摩擦焊,焊针转速为500 r/min,行进速度为100 mm/min。采用OM、EBSD和TEM对搅拌摩擦焊后的合金板材组织进行表征,并测试显微硬度和拉伸强度。结果表明,搅拌摩擦焊后,旋转焊针附近区域的纤维晶粒发生弯曲;轧制板材的织构逐渐减轻。在焊核区,细小的等轴晶尺寸仅为2.31μm。Al_3(Sc,Zr)粒子受到FSW的影响。搅拌摩擦焊后的粒子分布和粒子大小与原始板材不同。此外,Al_3(Sc,Zr)粒子的形状由球形变为多边形,许多粒子与Al基体变得不共格。搅拌摩擦焊板材的抗拉强度为367 MPa,屈服强度为263 MPa,原板材的强度分别为414 MPa和311 MPa。
An Al−Mg−Sc−Zr alloy rolled sheet was subjected to friction stir welding(FSW)with a tool rotation speed of 500 r/min and a tool travel speed of 100 mm/min.The microstructure of the alloy sheet after FSW was characterized by OM,EBSD and TEM.The microhardness and strength were also tested.The results show that after the FSW,the fiber grains adjacent to the rotating tool are bent.The texture of the rolled sheet is gradually alleviated.In the nugget zone,the size of the tiny equiaxed grains is only 2.31μm.Al3(Sc,Zr)particles are also affected by the FSW.The distribution and the size of the particles after the FSW are different from those of the original sheet.Moreover,the shape of the Al3(Sc,Zr)particles turns from spherical to polygonal and many particles become incoherent with the Al matrix.The tensile strength of the FSW sheet is 367 MPa and the yield strength is 263 MPa,and those of the original sheet are 414 and 311 MPa.
作者
蒋靖宇
姜锋
张梦晗
Jing-yu JIANG;Feng JIANG;Meng-han ZHANG(School of Metallurgy and Environment,Central South University,Changsha 410083,China;School of Materials Science and Engineering,Central South University,Changsha 410083,China;Light Alloy Research Institute,Central South University,Changsha 410083,China;National Key Laboratory of Science and Technology for National Defence on High-strength Lightweight Structural Materials,Central South University,Changsha 410083,China)
